Estimates of the number of children whose reading skills are significantly below expectation for their chronological and mental age have ranged from 10 to 30% of the total grade school population. Given the importance of literacy in our complex technological society, unexpected reading failure or dyslexia, represents a serious academic, employment and social problem for the children who experience this disorder. The proposal presented here represents an effort to establish a Major Research Program for the study of dyslexia. The center will be interdisciplinary in nature, drawing on researchers from the fields of psychology, linguistics, education and medicine. The basic orientation of the center is neuro-cognitive and a multi-step approach will be employed in the study of dyslexia. First, component parts of the reading task will be isolated. Second, the performance of dyslexic, normal, and learning disabled non-dyslexic children will be compared on those components of the task which are most likely to cause difficulty for the dyslexic. Third, where the dyslexic is found to be deficient with respect to the two control groups, further research will attempt to determine the cause of the difficulty. Because dyslexia has different manifestations and possibly different processes at different ages, a wide age range will be tested including children from preschool age till adulthood. The center will also conduct an active seminar and visiting scientist series. In addition to permitting the center's staff to keep abreast of the latest development, the series will also be open to school personnel interested in dyslexia. In this way, it is hoped to stimulate meaningful exchange between basic researchers and the practitioners who face the deep problems of working daily with dyslexic children.